2-Amino-4-{8 2-(1-lower alkyl-5-nitro-2-imidazolyl)-vinyl{9 -pyrimidines

ABSTRACT

This invention relates to 2-amino-4-(2-(1-lower alkyl-5-nitro-2imidazolyl)-vinyl)-pyrimidines and their use in the treatment of protozoal diseases and bacterial infections.

United States Patent 1 [111 3,882,105

Garzia 1 May 6, 1975 2-AMlNO-4-[2-( l-LOWER ALKYL-S-NITRO-2-IMIDAZOLYL)VlNYL}- PYRIMIDINES Aldo Garzia, Lodi, Italy lstituto Chemioterapico ltaliano S.p.A., Milan, Italy Filed: May 25, 1973 Appl. No.: 364,025

Related US. Application Data Continuation-impart of Ser. No. 309,483, Nov. 24, i972, abandoned.

Inventor:

Assignee:

US. Cl. 260/240 E; 260/240 A; 260/309;

424/251 Int. Cl C07d 51/42 Field of Search 260/240 A, 240 E Primary Examiner]0hn D. Randolph Attorney, Agent, or Firm-Morton, Bernard, Brown, Roberts & Sutherland [57] ABSTRACT This invention relates to 2-amin0-4-{2-( l-lower alkyl- S-nitro-Z-imidazolyl)-vinyl]-pyrimidines and their use in the treatment of protozoa] diseases and bacterial infections.

3 Claims, N0 Drawings 1 2-AMINO-4-[2-(l-LOWER ALKYL-S-NITRO-Z-lMIDAZOLYLJ-VINYL]- PYRIMIDINES This application is a continuation-in-part of application Ser. No. 309.483, filed Nov. 24, 1972, now abandoned, said application incorporated herein by reference.

This invention relates to novel compounds, processes for their preparation, and methods for their use in the therapeutic treatment of hosts afflicted with protozoa] diseases and bacterial infections. More particularly, this invention is directed to 2-amino-4-[2-( l-lower alkyl-5-nitro-2-imidazolyl)-vinyl]-pyrimidines as the novel compounds. The methods involve their anti-protozoal (e.g., anti-amebic)activity against pathogenic proto- 20a, and their anti-bacterial activity against pathogenic bacteria in living warm blooded animal bodies.

The novel compounds, which are active antiprotozoal and antibacterial agents, are particularly effective in therapeutically treating trichmononiasis, for instance, vulvovaginitis caused by Trichomonas vaginalis, by inhibiting the growth ofor destroying the microorganism (pathogenic protozoa) causing the disease. The compounds are also provided for the therapeutic treatment of bacterial infections caused by, for instance, microorganisms (pathogenic bacteria) such as Brucella brochiseptica, Salmonella pullorum, Streptococcus pyogenes, Diplococcus pneumoniae, Klesiella pneumoniae, and others, which microorganisms are inhibited in growth or destroyed by these compounds.

In one aspect, this invention relates to a method of treating vulvovaginitis, which is often caused by the protozoa Trichomonas vaginalis, and occurs in the female population with a high frequency and in males. Therefore, efforts have been put forth in searching for antitrichomonal agents which are very efficacious and non-toxic and, when administered to pregnant women, do not influence the regular development of the fetus. Desirably, the antitrichomonal agent should not adversely affect normal vaginal microflora, including Bacillus doderlein (Lactobacillus acidophilus).

Metronidazole, l-(2-hydroxyethyl)-2methyl-5- nitroimidazole, has been proposed for use as an antitrichomonal agent by Jacob et al. in US. Pat. No. 2,944,061, and is presently a frequently prescribed, commercially available drug for the treatment of vulvovaginitis. Although metronidazole is commonly employed for treatment of trichomoniasis, it has not been found to be completely satisfactory since certain strains of Trichomonas vaginalis has developed a resistance to the drug. Other proposals include the use of certain lower alkyl-2-( 2 substituted vinyl)-5-nitroimidazoles as an intermediate to sulfur-containing antiprotozoal agents by Miller et al. in U.S. Pat. No. 3,549,626, and the use of certain 2-(5nitro-2-furyl)vinyl pyrimidine derivatives as antitrichomonal agents by Minami et al. in US. Pat. No. 3,464,982.

An object of this invention is the provision of 2-amino-4-[ 2-( l -lower alkyl-5-nitro-2-imidazolyl)- vinyl-pyrimidines (hereafter the P-Compounds"), which may be represented by the structural formula n Lac wherein R is lower alkyl of one to about six, preferably one to about three, carbon atoms, to provide antiprotozoal and antibacterial activity, and especially to provide these P-Compounds for the treatment of vulvovaginitis. Exemplary of the PCompounds are 2-amino-4- {2-( lmethyl-5-nitro-2-imidazolyl )-vinyl]pyrimidine, 2-amino-4-[ 2-( l-ethyl-5-nitro-2-imidazolyl)-vinyl[- pyrimidine, 2-amino-4-[2-( lpropyl-5-nitro-2- imidazolyl)-vinyl]-pyrimidine, 2-amino-4-[2-( l-pentyl- 5-nitro-2-imidazoyl)-vinyl]pyrimidine, and the like.

One, or a combination, of the P-Compounds may be therapeutically administered, in microorganism-growth inhibiting amounts, to a living warm blooded animal suffering from a protozoa] disease or a bacterial infection caused by a microorganism. They may be adminis tered to the subject in any convenient form, for instance, in a pharmaceutical composition comprising a pharmaceutically-acceptable carrier and one or more of the P-Compounds, and exhibit activity in the urine and in the serum.

The P-Compounds are very efficacious against Trichomonas vaginalis even at low concentrations, say, at a concentration of about 1 or 2 micrograms per milliliter in in vitro tests. The amount of a P-Compound aclministered to a human patient suffering from trichomoniasis may frequently be from about 50 to 2,000 milligrams per day, especially for an individual weighing about 50 to kilograms.

The protozoa] diseases and bacterial infections which may be treated by the method of this invention include, as protozoa] diseases, trichomoniasis, enterohepatitis, amoebiasis, trypanosomiasis and enteric protozoal diseases, and, as bacterial infections, important Gram positive and Gram negative strains of pathogenic bacteria, particularly members of the coccus form of bacteria, including species of Diplococcus, Streptococcus and the like; and, for instance, species of Salmonella, Brucella, Klebsiella; and pleuropneumonia-like organisms (PPLO), the growth of which are inhibited by the P- Compounds. These compounds do not damage normal vaginal microflora, including Bacillus doderlein (Lactobacillus acidophilus).

The P-Compounds may be produced by a number of syntheses, for instance. by a dehydration reaction between wherein R is lower alkyl, as previously designated, and one of R and R" is and the other is -CH The reaction is conducted in the presence of dehydrating amounts of a dehydrating agent under dehydrating conditions including tempera tures which promote the dehydration reaction to react the formyl group and methyl group to yield water and provide the desired P-Compound. The dehydration conditions generally include ambient pressures and temperatures ranging from about 25 to 150C, preferably from about 30 to 90C.

The dehydrating agent is preferably a strong mineral acid and is advantageously employed in excess of that stoichiometrically required for completion of the reaction. Exemplary of strong mineral acids suitable for use as dehydrating agents are sulfuric acid, hydrochloric acid, phosphoric acid, and the like. Other acids, e.g., aromatic sulfonic acids containing from about six to l 1 carbon atoms, such as para toluene sulfonic acid, can be used. Lower fatty acid anhydrides, e.g., acetic anhydride, can also be used. The dehydrating agent can also be used as a solvent as well in solvent-providing amounts. Generally, the amount of dehydrating agent employed is at least about 1.1 times the stoichiometric amount required for completion of the reaction and may be 20 or 30 or more times that required for completion of the reaction when the dehydrating agent serves also as the solvent medium for the reaction. Greater amounts may be employed, but such amounts would appear to be impractical.

Suitable solvents are usually employed, preferably an organic carboxylic acid, e.g., an acyclic saturated monoacid containing from one to about six carbon atoms such as acetic or propionic acids, and among these, glacial acetic acid is preferred. The solvent is frequently provided in a weight ratio to the reactants including the dehydrating agent of at least about 2:1, preferably about 3:1 to l although greater amounts may be employed.

A particularly advantageous process for making the P-Compounds comprises reacting 5nitro-1-lower alkyl-Z-formyl imidazole, where the lower alkyl group corresponds to the lower alkyl group at the 1 position on the imidazolyl nucleus. For instance, one process for the preparation of 2-amino-4-[2-( l-methyl-S-nitro-Z- imidazolyl)-vinyl]-pyrimidine (the P'-Compound") comprises reacting S-nitro-l-methyl-Z-formyl imidazole with 2-amino-4-methyl pyrimidine to provide the P'-Compound. The 2-amino-4-methyl pyrimidine may be used in a slight stoichiometric excess, e.g., about 1 to 50 weight percent in excess of that required to react with the imidazole reactant, and the reaction is advantageously conducted in the presence of a dehydrating agent, preferably at temperatures from about 30 to 90C., advantageously from about 35 to 75C. The resultant reaction mixture may be diluted with Water and neutralized with a suitable base, for instance, a saturated solution of sodium bicarbonate, to form the novel compound as a precipitate.

S-Nitro- 1 -lower aIkyl-Z-formyl imidazole is disclosed in Henry et al., U.S. Pat. No. 3,472,864, and several methods of its preparation are disclosed therein. For

instance, S-nitro-1-methyl2-formyl imidazole can be prepared by contacting S-nitro-l ,2-dimethyl imidazole with selenium dioxide, and heating the mixture until the reaction begins, as indicated by the evolution of heat. On conclusion of the exothermic reaction, the mixture is cooled, and the imidazoles are separated by extraction into an organic solvent. A final purification may be facilitated by the formation of an insoluble aldehyde derivative such as an oxime, hydrazone, or semicarbazone. Another method of obtaining 5-nitro-l-methyl-Z-formyl imidazole is by the reaction of 1-methyl-5-nitroimidazo1e with trioxymethylene in a dimethyl sulfoxide solution in a sealed tube to form 1- methyl2-hydroxymethyl-5-nitroimidazole which can be oxidized with an oxidant such as lead tetra-acetate, manganese dioxide, nitrogen tetroxide, dimethylsulfoxide-dicyclohexyl carbodiimide, nitric acid or pyridine chromium trioxide complex or with other reagents capable of converting the 2-hydroxymethyl substituent to a l-formyl radical.

2-Amino4-methyl pyridimine can be obtained from the reaction of guanidine hydrochloride and chlorovinylmethyl ketone as is well known in the art, and the compound is reported, for instance, as compound P- 2100 in The Handbook of Chemistry and Physics, 46th edition, page C-523. Other preparations of pyrimidine may be found in, for instance, Gillman, Organic Chemisrry in Advanced Treatise, Volume 4, page 866 et seq. (1953).

Another process for preparation of the P Compounds comprises reacting 2-arnino-4-(dialkoxymethyl)-pyridimine, a precursor to 2-amino-4-formylpyrimidine, where the alkoxy groups may be the same or different and may be lower alkoxy of 1 to about 6 carbon atoms, preferably ethoxy, with l-lower alkyl-2- methyl-5nitroimadazole wherein the lower alkyl group corresponds to the lower alkyl substituent of the compound. The acetal structure, in the presence of aldehyde-forming amounts of water, will provide the corresponding aldehyde and alcohol. The conversion of the acetal to aldehyde may occur in the same reaction simultaneously with the dehydration reaction to provide the P-Compounds, or the aldehyde may be prepared prior to conducting the reaction with the imidazole component to provide the P-Compounds.

The amount of water available for reaction with the acetal should preferably be in excess of the stoichiometric amount required to provide the desired amount of pyrimidine component for the reaction to produce the P-Compounds. For instance, when the acetal is being reacted in the presence of the imidazole component, thus the Z-amino-4-formyl-pyrimidine is being prepared in situ, the water liberated from the dehydration reaction may serve to react with the acetal on the pyrimidine group. It may be desirable to employ only catalytically-effective amounts of water to initiate the reactions, for instance, about 0.01 or 1 to 50 percent of the amount of water required to provide the desired amount of aldehyde. Excessive amounts of water may reduce the effectiveness of the dehydrating agent. Since the acetal and aldehyde are in an equilibrium relationship, it is often preferable to provide the acetal in an amount in excess of that stoichiometrically required for reaction with the imidazole component in order to favor the production of the aldehyde, for instance, about 1.1 to 5 times the amount required. If the acetal is converted to the aldehyde prior to conducting the reaction between the pyrimidine and imidazole compo' nents to prepare the P-Compounds of this invention, the water may be employed in excess of the amount stoichiometrically required for the desired degree of converstion, e.g., about l.l to 10, preferably L5 to 5, times the amount required. Generally, a temperature in the range of about 25 to l50C. may be employed. For example, the P-Compound (where R is methyl) can be prepared through the reaction of 2-amino-4- (diethoxymethyl) pyrimidine, which is described in J. Am. Chem. Soc, Volume 69, page 3072 (1947), with l.Z-dimethyl-S-nitroimidazole, which is described in J. Chem. $00., Volume l27, page I832 (I925).

The dehydration reaction to provide the P- Compounds may be conducted in two stages. First, the aldehyde and methyl group may be reacted in the presence of a strong base in excess of the amount stoichiometrically required for reaction, e.g., about 1.1 or 1.5 to l0 to times, to form a secondary alcohol, and then the secondary alcohol can be dehydrated with a dehydrating agent as described above.

The P-Compounds may be administered, for therapeutical purposes, to a host in any convenient manner. For example, one of the P-Compounds may be topically applied on the affected area, orally administered, or parenterally administered, for instance, by cutaneous, subcutaneous, intravenous, and the like, injections. Oral and topical treatments are generally preferred for vulvovaginitis due to the ease of administration. Generally, the amount of a P-Compound administered to a human patient to achieve antitrichomonal activity is about 50 to 2,000 milligrams per day, especially for an individual weighing about 50 to 70 kilograms. In females, the amount administered is preferably from about 200 to 1,000 milligrams per day, and for males, about 100 to 800 milligrams per day is preferred. Normally, the dosage amount in treating living warm-blooded animal bodies having a protozoal disease or bacterial infection which is therapeutically responsive to a P-Compound is about I to 40, preferably about 4 to 20, milligrams of the compound per kilogram of body weight per day. A P-Compound may be administered once a day, or fractionally at periodic in tervals throughout the day. When orally administered, two or three or more fractional doses per day are preferred.

For oral administration, a P-Compound is usually compounded in a pharmaceutical unit dosage from such as pill, lozenge, tablet or capsule with a pharmaceutically-acceptable carrier. Such unit dosage forms, for example, containing from about 50 to about 500 milligrams of a PCompound, are quite satisfactory and are prepared according to techniques known to those skilled in the art. Thus, these unit dosage forms will contain the normal diluents, excepients, lubricating agents, and extenders regularly employed in compounding such forms. Exemplary carriers are solids such as lactose, magnesium stearate, calcium stearate, starch, terra alba, dicalcium phosphate, sucrose, talc, stearic acid, gelatin, agar, pectin, or acacia.

Alternatively, a P-Compound may be suspended in or dissolved in liquid vehicles suitable for oral administration. The final preparation may be in the form of a solution, emulsion, suspension, syrup, or the like. Liquid carriers which may be employed include, for instance, peanut oil, sesame oil, olive oil, water, and the like. The

6 liquid preparation may also include wetting agents and other conventional additives for liquid pharmaceutical dosage forms.

For topical administration, topical jellies, creams, ointments, or suppositories are normally used. Vaginal inserts containing, as inactive ingredients, lactose, starch, hydrogenated castor oil, polyvinyl alcohol or other water soluble, non-toxic polymer, and the like are commonly used. Vaginal inserts are normally used once a day for convenience and are often supplemented with, for instance, oral administration of a P Compound.

A P-Compound may also be contained in a suitable, sterile solution or suspension in a pharmaceutically acceptable carrier for parenteral injections. In addition, P-Compounds used in the method of this invention for inhibiting the growth of or destroying microorganisms which cause protozoa] diseases or bacterial infections, or in compositions containing the same, may be either administered in amounts sufficient to produce the desired anti-protozoal or anti-bacterial effects upon administration of a unit dosage form of one or more P- Compounds, together with or include other physiologically active materials and/or medicants, e.g., buffering agents, antacids, sedatives, tranquilizers, analgesics, or the like.

The P-Compounds also may be used in veterinary medicine in the treatment of bacterial and protozoa], particularly trichomonad infections. For instanace, they may be used to treat Trichomonas fetus in cattle. Trichomonas fetus causes abortion and sterility in cattle.

It will be understood that the P-Compounds of this invention as used to treat protozoa] or bacterial infections can be brought into a unit dosage form by any suitable technique known to one of ordinary skill in the art.

The following examples are provided to further illustrate this invention. All parts and percentages are by weight unless otherwise stated.

EXAMPLE 1 Into a mixture of L6 grams of 2-amino-4-methylpyrimidine with 10 milliliters of glacial acetic acid is slowly added 2.13 grams of concentrated sulfuric acid. A mixture of 2.4 grams of 2-formyl-l-methyl-5- nitroimidazole in 20 milliliters of glacial acetic acid is slowly added to the mixture of the pyrimidine under stirring. The reaction mixture is maintained at a temperature of about 55C. for 4 hours. The resultant mixture is then diluted with 200 milliliters of distilled water and neutralized with a saturated aqueous solution of sodium bicarbonate. A brownish-yellow precipitate is formed and recovered. The product is analyzed by infrared spectroscopy and is found to conform to 2- amino4-[2-( l-methyl-5-nitro-2-imidazolyl )-vinyl pyrimidine.

EXAMPLE ll In vitro tests to determine the activity of 2-amino-4- [2-( l -methyl-5-nitro-2-imidazolyl )-vinyl]-pyrimidine against Trichomonas vaginalis are conducted using three strains of the protozoa: Serafino Belfonti strain, hereinafter designated as S, obtained from the Institute of Serum Therapy of Milan, and strains Cl and C2, obtained from Professor Cantoni of the Institute of Inspection of Foods of Animal Origin of the University of Milan. The medium for the maintenance of the strains TABLE 2 is of the type disclosed as the Simplified Tripticase Serum by Kupferberg et al. in Proceedings ofihe Society Tmhommw vagina; Strain S of Experimental Biological Medicine, Volume 67, p. Microscopic Examination 304, 1948, to which O.l weight percent of chloram- 5 f d ICI' phenicol has been added. The chloran' phenicol serves 'fi,'{i f}f gf, g fifi per to impede the development of contaminating bacteria, Comm L5 20 but is inactive against Trichomonas vaginalis at this low 1 VM SM I I 1 concentration. Prior to use, the medium is raised to a F Ii VM SM 1 I 1 temperature of lO0C. for about two to three minutes a L to remove a significant amount of oxygen from the me- MET 1] W M M SM dium. After cooling to about 37C., 0.5 weight percent VM M M 5M l of human serum is added under sterile conditions. To Cum": Appearance about 9 milliliters of this medium is added about 0.25 l VT ST ST C C F ii VT ST 0 c c to 0.30 milliliter of theprevlous broth, and transfers to m w ST C C C new broths for the maintenance of the strains are car- I VT T T T ST ried out every 48 to 72 hours. The incubation of the MET a 1 :F T strains is at 37C.

The three strains are employed to determine the elficacy of 2-amino-4-[2-(1-methyl-5-nitro-2-imidazolyl)- TABLE 3 vinyll-pyrimidine by transferring a standard 0.25 to 0.30 milliliter inoculum to a new 9 milliliter broth con- T h r S r S IIC omnnas VG ma IS train tainmg 0.5, L5 or 2.0 micrograms of the corn- MicroscopfEmminalion pound per milliliter. After 48 to 72 hours, the broth is examined visually for the degree of turbidity in the culi fi gr gg' gfi per ture tubes, and thus the development of the protozoa. Run Control 0.5 1.0 L5 2.0 The turbidity due to the coagulation of the protein of the serum is distin uished from the develo merit of the l W SM I I l g P F ii VM SM l l l protozoa due to the decolorization of the medium since III VM SM l I l the development of the protozoa is accompanied by a MET m a: m reduction of the methylene blue in the medium. The in VM M M M M broth 15 also examined using a phase contrast micro- Culture Appearance scope to evaluate the degree of mobility or lack of mol VT ST C C C bility of the Trichomonas vaginaiis. The microscopic F T 3 g g examinations also show the morphology of the cells in VT T T 5T C that young cells have a pear-shaped structure whereas MET ll VT T T 5T C lll VT T T ST ST older cells are more rounded. As a comparison, identical tests are conducted using metronidazole as the active ingredient. Controls are run using no active ingre- L dient. The results are provided in Tables I to 6 wherein TAB E 4 the following symbols are employed: 2-amino-4-[2-( lmethyl-S-nitro-Z-imidazolyl)-vinyl]-pyrimidine (P'- g gfgg g 'gtgf S Compound) is represented as F; metronidazole, MET; cells very mobile, VM; cells mobile, M; cells slightly g 'fi fi gzgg' g g mobile, SM; cells immobile or absent, I; culture very Run Comm] ()5 L0 L5 10 turbid, VT; culture turbid, T; culture slightly turbid, ST; culture clear C. F i i Ill VM l l l I TABLE 1 l VM VM 1 l l MET ll VM M SM l l Trichumunas vaginal'is Strain S In VM M SM l I Microscopic Examination Culmre Appearance Microgram active compound per F I} g g g g g milliliter of broth In W ST C C C Run Control 0.5 L0 1.5 2.0 l W T C C C MET ll VT T ST C C 1 VM VM 5M 1 1 lm VT T ST c C F ll VM VM SM 1 i in vM VM SM 1 i 1 VM vM M SM 1 MET ll VM VM M SM I liii VM VM M SM i TABLE 5 (alum App-iamnce ST C C Trichomonas vaginalis Strain Cl F H VT T ST C C Microscopic Examination lll VT T ST C C M.

1 VT VT T ST C icrogram active compound per MET VI. W T ST C milliliter of broth m VI. W T ST C Ruri Control 0.5 L0 1.5 2.0

I 1 VM SM 1 l I F l [1 VM I l l I [I] l l TABLE -Continued 'I'rlc/mmrmas vaginulis Strain Cl Microscopic Examination Microgram active compound per milliliter of broth TABLE 7-Continued Microscopic evaluation at 24 hours after addition of active compound Microgram active compound per milliliter of broth Run Control 0.5 l .0 2.0 Strains Control 0.5 1.0 1.5 2.0

1 VM M M SM i 5 VM VM M M SM MET ll VM M M SM t MET Cl VM M M M SM in VM M M SM r 10 c2 vM M M M SM Culture Appearance VT ST C E g ill VT ST C A in] VT ST C C C TABLE 8 l VT T T ST C MET a Microscopic evaulation at 48 hours after addition of active compound Microgram active compound per milliliter of broth TABLE, 6 Strains Control 0.5 [.0 l.5 2.0

y s M SM Trz'chumonas vaginalilt Strain C2 F Cl M SM Microscopic Examination C2 M SM SM SM I M M M M l Micrograrn active compound per MET Cl M M M SM 1 milliliter of broth M M M M 1 Run Control 0.5 1.0 l5 2.0

l VM SM l l i F It: 5;" i l The results summarized in Example Ill illustrate that 1 VM VM M SM 1 the P-Compounds inhibit Trichomomzs vaginalis, in- MET it VM VM M SM I eluding resistant strains of the microorganism, at sub- VM M M SM l stantially lower concentrations in vitro tests than met- Culture Appearance ronidazole. l VT ST c c c F ii VT 0 c c c EXAMP lll VT T C C C LE Iv MFT a 1 g The activity of 2-amino-4-[2-( lmethyl-5-nitro-2- m VT W T T C imidazolyl)-vinylLpyrimidine against certain other mi croorganisms is determined by the use of the well known streak plate method. The microorganisms are The results summarized in Example ll illustrate that obtained from a 24-hour slant of Difco Brain Heart inthe P-Compound inhibits Trichomonas vaginalis, in- 40 fusion Agar which is incubated at 37C. The streaks are eluding resistant strains of the microorganism, at a substantially lower concentration in the in vitro test, than metronidazoie.

EXAMPLE lll 2-Amino-4-[2-( l-methyl-5-nitro-2-imidazolyl)- vinyl]-pyrimidine is tested to determine its effect in vitro on mature cultures of Trichomrmas vaginalt's. Nine milliliter samples of strains S, C1, and C2 of Trichomonas vaginalis are prepared in accordance with Example H and incubated for 48 hours. The cultures are then transferred to sterile tubes containing the same concentrate of active compound as in Example ll. Microscopic evaluations for mobility are conducted after 24 and 48 hours of incubation after the addition of the active compound. The results are provided in Tables 7 and 8 with the same symbols being employed as in Tables 1 to 6. Visual evaluation of the broth is not taken into consideration due to the nature of the test.

TABLE 7 Microscopic evaluation at 24 hours LlflCl' addition of active compound Microgram active compound per made with a suspension of the microorganism in 5 to 6 milliliters of sterile physiological solution. In the case of the strains belonging to the group of mycetes, Difco Malt Agar broth is used and incubation is at 30C. The streaks so prepared, are incubated for 24 hours. The results are provided in Table 9.

TABLE 9 Minimal inhibitory concentration (microgram of active compound per milliliter of broth) F Microorganism MET Aembacrer aerogenes 20 l I00 )0 Bacillus cereus var. mymidcs ATCC 9634 1 2.525 l00 Bacillus subrilis ATCC 6633 l 2.5 Bmcella hmncliiseplica 12.5 100 Escherichia coli 46 (l 100 100 Micmcoccus flavur ATCC l0240 100 100 Proteus mirabilis fil (l 100 lOU Proteus vulgaris ATCC (1897 100 100 Pseudrmmmr aemginnm 77 1 l 100 l00 Salmonella pullorum ATCC 9120 l2.5 lUO Salrmmella lyphimurium 100 [00 Shlgella dissenleriae Madsen t l 100 100 Smphylnaxctw aureus I68 l 2) l00 I00 Streptococcus faemlis 100 I00 Streptococcus pyogenes l 2.5 100 Drplococcm pneumoniue l 2. i I00 Klebsiella pneumrmi'ae 12 100 Candida albicans 106 100 Schizosaccharomyces pumbe I (K) l00 Aspergillus m'ger 100 100 TABLE 9-Continued Minimal inhibitory concentration (microgram of active compound per milliliter of broth) M icroorganism F MET Aspergillus flaws l 100 (l I Virulent strain Isolated in hospital (2: Penv'illinresistanl strain It is demonstrated through Example IV that the P- Compounds can be classified a limited spectrum antibacterial agent in that microorganisms which are Gram positive as well as a few Gram negative types are inhibited at 12.5 t g/ml or less.

EXAMPLE V Four female patients suffering from vulvovaginitis are orally administered 2-amino-4-[2-( l-methyl'5- nitro-2-imidazolyl)-vinyl]-pyrimidine in the amount of 500 milligrams per day. Two of the patients continue the treatment for l day. and the other two continue the treatment for 3 days. Urine samples are taken and are evaluated to determine the concentration of the active compound therein, In all cases, the concentration of the active compound in the urine is maintained at least three times as much as the average concentration required to kill Trichomonas vaginalis in vitro.

EXAMPLE VI Six female patients who are to undergo colpohysterectomy are orally administered two capsules containing 250 milligrams of 2-amino-4-[2-( l-methyl-S-nitroQ- imidazolyll-vinyl]-pyrimidine each per day for a few days prior to surgery. The concentration of the active compound is determined microbiologically using plates of vaginal homogenates. The concentration is found to be about 8 micrograms per gram of homogenate.

EXAMPLE VII Thirty female patients suffering from vulvovaginitis and having Trichomonas vaginalis present in the vaginal secretion, are orally administered two capsules containing 250 milligrams of 2-amino-4-[2-(l-methyl5- nitro-Z-imidazolyl)vinyll-pyrimidine each per day. After days, the presence of Trichomonas vaginalis is not found, and no sign of leukorrhea is observed, evidencing successful treatment. In comparison, using metronidazole administered orally in the same amount, ten days of medication are usually required for complete treatment.

As with other imidazole-containing drugs, some secondary effects may be reported in select cases such as nausea, diarrhea, bad breath, urticaria, uretheral and vaginal burning, dizziness, headache, insomnia, and in Lil rare cases, temporary leucopenia.

EXAMPLE VIII Example I is repeated except employing as reactants I ,Z-dimethyl-S-nitroimidazole and 2-amino-4- (diethoxymethyl)-pyrimidine. The concentrated sulfuric acid (98%) provides sufficient water to initiate and sustain the conversion of the diethoxymethyl group on the pyrimidine to a formyl group and ethanol, and 2- amino-4-[2-( l-methyl-5-nitro-2-imidazolyl)-vinyl]- pyrimidine is formed in situ.

EXAMPLE IX Example I is repeated except employing, as reactants, 2-amino-4-methyl pyrimidine and 2-formyl-I-ethyl-5- nitroimidaole, 2-Amino-4-[2-( l-ethyl-5-nitro-2- imidazolyl)-vinyl]-pyrimidine is formed. It is recovered and a sample is used to in vitro inhibit the growth of Trichomonas vaginalis in accordance with Example I]. Another sample is used to form a dosage unit capsule of 250 milligrams, and two capsules per day are orally administered to therapeutically treat a patient suffering from trichomoniasis.

EXAMPLE X or -Ic= wherein R is lower alkyl of one to about six carbon atoms.

2. The compound of claim 1 wherein R is lower alkyl of one to about three carbon atoms.

3. The compound of claim 1 wherein R is methyl. 

1. A COMPOUND OF THE FORMULA
 2. The compound of claim 1 wherein R is lower alkyl of one to about three carbon atoms.
 3. The compound of claim 1 wherein R is methyl. 